Abstract

The Hopfield emission bands of oxygen are shown to arise from a transition in the O2+ molecule. The upper state is new, designated c4Σu—, assuming an allowed transition, while the lower state is the known b4Σg— state. The single observed vibrational level of the c4Σu— state lies at 24.56 eV above the ground state of the O2 molecule. The rotational constantB of the upper state vibrational level has a value of 1.557 cm—1.